British ferns (Filicopsida)


L. Watson and M. J. Dallwitz

Dryopteris filix-mas (L.) Schott

“Male Fern”.

Sporophyte. The rhizomes short, stout; more or less erect; bearing scales (densely scaly, with broad, soft scales). Plants with no clear distinction into fertile and sterile leaves.

Leaves aggregated terminally (crowns solitary or few); to (30–)50–150(–180) cm long (i.e., usually over 50 cm); usually dying in the autumn; compound; complexly divided; once pinnate, with conspicuously divided pinnae (the pinnules crenate-serrate all round, with erect or convergent teeth at the apex). Pinnae 20–35 on each side of the leaf. The petioles shorter than the blades (sparsely or moderately covered with uniformly pale brown scales, the larger of these ovate and long-acuminate); about 0.2–0.4 x the length of the blade (about a quarter to almost half as long); vascularised by several discrete strands (derived via 5 or 7 leaf traces). Petiolar scales not golden brown (pale brown to straw-coloured, rather numerous). The longest pinnae around the middle of the blade (the pinnae decreasing in length basipetally, the lowest about 4/5 the length of the longest); 5–15 cm long. The pinnae decreasing markedly in length towards the base of the blade, the basal ones relatively short. The bases of the pinnae without a dark blotch at the base. The venation of the lamina open.

The sporangia superficial; protected; aggregated in sori. The sori sub-orbicular (relatively large, about 1 mm in diameter, borne 5–6 on each side of the midrib of the largest pinnules); remaining discrete at maturity; 5–6 on either side of the mid-rib of the larger pinnules (and at least 3 on the majority of them); with a true indusium. The indusia reniform and attached at the indentation; entire, not glandular, not embracing the sporangium. The mature spores monolete; without a perispore.

Distribution and habitat. Probably on base-rich substrates, on neutral substrates, and on acid substrates. Woods, hedgebanks, ditches, in open or shade, at low and high elevations. Common throughout the British Isles.

Vice-county records. Britain: West Cornwall, East Cornwall, South Devon, North Devon, South Somerset, North Somerset, North Wiltshire, South Wiltshire, Dorset, Isle of Wight, South Hampshire, North Hampshire, West Sussex, East Sussex, East Kent, West Kent, Surrey, South Essex, North Essex, Hertfordshire, Middlesex, Berkshire, Oxfordshire, Buckinghamshire, East Suffolk, West Suffolk, East Norfolk, West Norfolk, Cambridgeshire, Bedfordshire, Huntingdonshire, Northamptonshire, East Gloucestershire, West Gloucestershire, Monmouthshire, Herefordshire, Worcestershire, Warwickshire, Staffordshire, Shropshire, Glamorgan, Breconshire, Radnorshire, Carmarthenshire, Pembrokeshire, Cardiganshire, Montgomeryshire, Merionethshire, Caernarvonshire, Denbighshire, Flintshire, Anglesey, South Lincolnshire, North Lincolnshire, Leicestershire, Nottinghamshire, Derbyshire, Cheshire, South Lancashire, West Lancashire, South-east Yorkshire, North-east Yorkshire, South-west Yorkshire, Mid-west Yorkshire, North-west Yorkshire, Durham, South Northumberland, North Northumberland, Westmorland, Cumberland, Isle of Man, Dumfriesshire, Kirkcudbrightshire, Wigtownshire, Ayrshire, Renfrewshire, Lanarkshire, Peeblesshire, Selkirkshire, Roxburghshire, Berwickshire, East Lothian, Midlothian, West Lothian, Fifeshire, Stirlingshire, West Perthshire, Mid Perthshire, East Perthshire, Angus, Kincardineshire, South Aberdeenshire, North Aberdeenshire, Banffshire, Moray, East Inverness-shire, West Inverness-shire, Argyll Main, Dunbartonshire, Clyde Isles, Kintyre, South Ebudes, Mid Ebudes, North Ebudes, West Ross, East Ross, East Sutherland, West Sutherland, Caithness, Outer Hebrides, Orkney islands, Shetland, Channel Islands. Ireland: South Kerry, North Kerry, West Cork, Mid Cork, East Cork, Waterford, South Tipperary, Limerick, Clare, North Tipperary, Kilkenny, Wexford, Carlow, Leix, South-east Galway, West Galway, North-east Galway, Offaly, Kildare, Wicklow, Dublin, Meath, West Meath, Longford, Roscommon, East Mayo, West Mayo, Sligo, Leitrim, Cavan, Louth, Monaghan, Fermanagh, East Donegal, West Donegal, Tyrone, Armagh, Down, Antrim, Londonderry.

Classification. Family Polypodiaceae (C.T.W.); Dryopteridaceae (Swale and Hassler); Dryopteridaceae (Stace). Order Dryopteridales (Swale and Hassler).

D. x complexa Fraser-Jenk. = D. affinis x D. filix-mas; D. x brathaica Fraser-Jenk. & Reichst. = D. filix-mas x D. carthusiana.

Illustrations. • P. vulgare: Eng. Bot. 1850 (1886). • D. filix-mas: Sowerby and Johnson (1859). • D. filix-mas: details of sorus and sporangia (Goebel). • 9 British Dryopteridaceae (inter alia).

To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2004 onwards. British ferns (Filicopsida). Version: 4th January 2012.’.